/* Copyright (c) 2004-2006, Sara Golemon <sarag@libssh2.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms,
 * with or without modification, are permitted provided
 * that the following conditions are met:
 *
 *   Redistributions of source code must retain the above
 *   copyright notice, this list of conditions and the
 *   following disclaimer.
 *
 *   Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials
 *   provided with the distribution.
 *
 *   Neither the name of the copyright holder nor the names
 *   of any other contributors may be used to endorse or
 *   promote products derived from this software without
 *   specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 */

#include "libssh2_priv.h"

/* {{{ libssh2_ntohu32
 */
unsigned long libssh2_ntohu32(const unsigned char *buf)
{
	return (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];
}
/* }}} */

/* {{{ libssh2_ntohu64
 * Note: Some 32-bit platforms have issues with bitops on long longs
 * Work around this by doing expensive (but safer) arithmetic ops with optimization defying parentheses
 */
libssh2_uint64_t libssh2_ntohu64(const unsigned char *buf)
{
	unsigned long msl, lsl;

	msl = (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];
	lsl = (buf[4] << 24) | (buf[5] << 16) | (buf[6] << 8) | buf[7];

	return ((msl * 65536) * 65536) + lsl;
}
/* }}} */

/* {{{ libssh2_htonu32
 */
void libssh2_htonu32(unsigned char *buf, unsigned long value)
{
	buf[0] = (value >> 24) & 0xFF;
	buf[1] = (value >> 16) & 0xFF;
	buf[2] = (value >> 8) & 0xFF;
	buf[3] = value & 0xFF;
}
/* }}} */

/* {{{ libssh2_htonu64
 */
void libssh2_htonu64(unsigned char *buf, libssh2_uint64_t value)
{
	unsigned long msl = (value / 65536) / 65536;

	buf[0] = (msl >> 24) & 0xFF;
	buf[1] = (msl >> 16) & 0xFF;
	buf[2] = (msl >> 8) & 0xFF;
	buf[3] = msl & 0xFF;

	buf[4] = (value >> 24) & 0xFF;
	buf[5] = (value >> 16) & 0xFF;
	buf[6] = (value >> 8) & 0xFF;
	buf[7] = value & 0xFF;
}
/* }}} */

/* Base64 Conversion */

/* {{{ */
static const char libssh2_base64_table[] =
    { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
      'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
      'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
      'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
      '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/', '\0'
    };

static const char libssh2_base64_pad = '=';

static const short libssh2_base64_reverse_table[256] = {
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
    52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1,
    -1,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
    15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
    -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
    41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
};
/* }}} */


/* {{{ libssh2_base64_decode
 * Decode a base64 chunk and store it into a newly alloc'd buffer
 */
LIBSSH2_API int libssh2_base64_decode(LIBSSH2_SESSION *session, char **data, int *datalen,
																char *src, int src_len)
{
	unsigned char *s, *d;
	short v;
	int i = 0, len = 0;

	*data = d = LIBSSH2_ALLOC(session, (3 * src_len / 4) + 1);
	if (!d) {
		return -1;
	}

	for(s = src; ((char*)s) < (src + src_len); s++) {
		if ((v = libssh2_base64_reverse_table[*s]) < 0) continue;
		switch (i % 4) {
			case 0:
				d[len] = v << 2;
				break;
			case 1:
				d[len++] |= v >> 4;
				d[len] = v << 4;
				break;
			case 2:
				d[len++] |= v >> 2;
				d[len] = v << 6;
				break;
			case 3:
				d[len++] |= v;
				break;
		}
		i++;
	}
	if ((i % 4) == 1) {
		/* Invalid -- We have a byte which belongs exclusively to a partial octet */
		LIBSSH2_FREE(session, *data);
		return -1;
	}

	*datalen = len;
	return 0;
}
/* }}} */

#ifdef LIBSSH2_DEBUG_ENABLED
/* {{{ _libssh2_debug
 * Internal debug logging facility
 * Just writes to stderr until a good reason comes up to support anything else
 */
void _libssh2_debug(LIBSSH2_SESSION *session, int context, const char *format, ...)
{
	char buffer[1536];
	int len;
	va_list vargs;
	char *contexts[9] = {	"Unknown",
							"Transport",
							"Key Exhange",
							"Userauth",
							"Connection",
							"scp",
							"SFTP Subsystem",
							"Failure Event",
							"Publickey Subsystem",
						 };

	if (context < 1 || context > 8) {
		context = 0;
	}

	len = snprintf(buffer, 1535, "[libssh2] %s: ", contexts[context]);

	va_start(vargs, format);
	len += vsnprintf(buffer + len, 1535 - len, format, vargs);
	buffer[len] = '\n';
	va_end(vargs);
	write(2, buffer, len + 1);
}
/* }}} */
#endif
